Indoor environmental conditions and likelihood of reported violence and aggression in a purpose-built residential dementia hospital

This study, conducted on purpose-built NHS dementia wards, investigates correlations between patient aggression and indoor temperature and humidity. Temperature and humidity, measured at 3-min intervals, on male and female wards, over 12–15 months, were compared against staff-recorded incidents (n = 299; females n = 100; males n = 199). Linear regression was used to assess potential correlations. Binomial analysis measured relative risk of incidents outside comfortable thermal (22–24 °C) and humidity (30%–60%) ranges. Temperatures ranged from 17 to 27oC and humidity ranged from 16 to 70%. On the male ward, both extremes of temperature were correlated with increased incident likelihood (R2 = 0.473) and relative risk of incidents was 1.89 (p = 0.0015) at temperatures <22oC and 1.73 (p < 0.001) at temperatures >24oC. On the female ward, increasing temperature was correlated with increased incident likelihood (R2 = 0.568) and relative risk of incidents was 1.99 (p < 0.001) at temperatures >24oC. Strong associations between relative humidity levels and incidents were not identified. Extreme temperatures were associated with significantly increased risk of incidents of agitation, suggesting relevance of environmental conditions in the formulation of agitation in dementia.